Before he sinned he did not have a sin nature. He was never perfect (in this life, but I believe he is now in glory).
How could he be tested? Isn’t mature character tied to loyalty, love, obedience? What was he lacking that made him fail?
He didn’t seem to obey like Jesus, David, Daniel, Joseph, Job, etc. Many humans are commended for their trust and love for God who fail, only a few who almost perfectly obey. Only the Last Adam obeyed selflessly and in love. Adam was without a sin nature so why didn’t he love/obey God?
That brings up an interesting point
Because the angels who fell, following Satan who fell- they were created perfect. Lucifer was perfect until sin was found in him. His heart- his pride led him to sin.
Adam was sinless the same way the angels were, created without sin.
But what is the first commandment?
You shall have no other gods before Me
Satan became a god in his own heart- Isaiah 14:12-15 has the 5 I Will statements.
"“I will ascend to the heavens;
I will raise my throne
above the stars of God;
I will sit enthroned on the mount of assembly,
on the utmost heights of Mount Zaphon.
14 I will ascend above the tops of the clouds;
I will make myself like the Most High.”"
And what does the fruit mean? Genesis 3 tells us here
4Then the serpent said to the woman, “You will not surely die.
5 For God knows that in the day you eat of it your eyes will be opened,
and you will be like God, knowing good and evil.”
6 So when the woman saw that the tree
was good for food, that it
was pleasant to the eyes, and a tree desirable to make
one wise, she took of its fruit and ate. She also gave to her husband with her, and he ate.
Both Satan and Adam were created perfect. Both sinned. Both chose to put someone above God.
Satan put himself above God.
Adam put his own desires (whether to please or protect or even placate Eve, or simply for the fruit to make him like God) above God.
Both meant they were desiring to be as God. Putting themselves in God's place.
The sin is idolatry. In both cases self came before God.
Does God create sin in either one? NO. He did create the angelic realm and human beings with free will. So they were perfect, but they had a will. The question was whether they would yield that will to God.
His test which Jesus passed (on one of the other threads on this topic I think) was whether or not His sinless perfect creations would pass the test and put Him first.
Satan fell, a number of the angels fell, Adam fell.
When Adam fell all humanity that came from him fell, and the Creation which he was created to rule over fell too. God had a plan before it all happened. He knew.
This means that the fall and our Redemption in Christ was something God took care of before anything came into being.
God's grace meant that He used the seed of the woman which was to come to bring about the Redemption that the original woman made necessary.